The present invention is an improvement on the portable terminal wrapping tool disclosed in U.S. Pat. No. 4,284,109 issued to P. R. Kilmer and R. M. Bula. The disclosure of this patent, incorporated by reference herein, describes one type of power tool system in which the improvements of the present invention may be employed. The terminal wrapping tool described in the Kilmer and Bula '109 patent is a light weight, convenient, reliable, and reasonably low cost unit. The improvements hereinafter disclosed further enhance the wear characteristics, associated with the gear reduction mechanism employed to couple drive torque from the electric drive motor to the rotatable tool bit. Drive train noise and vibration are reduced. Manufacturability of the drive mechanism is enhanced since the design permits relaxation of certain alignment tolerances without sacrificing performance. Convenience of use is increased by the provision of a readily adjustable index mechanism for controlling the starting angular position of the tool bit.